Oyster-dredging machine



(No Model.)

w. B. COLLIER.

OYSTER DREDGING MAGHINEi No. 246,726. Patented Sept. 6,1881.

WITNESSES ATTORNEYS.

N. prrzns Phnlo-Lithograplmr. Washillgion, n. c.

'UNITED STATES PATENT Drrrce.

WILLIAM B. COLLIER, OF ELLICOTT CITY, MARYLAND.

OYSTER-DREDGING MACHINE.

SPECIFICATION forming part of Letters Patent No. 246,726, dated September 6, 1881.

' Application filed July 14, 1881. (No model.)

To all whom it may concern:

Be it known that I, WILLIAIVI B. COLLIER, of Ellicott City, in the county of Howard and State of Maryland, have invented a new and useful Improvement in Dredging-Machines and I do herebydeclare that the followingisa full, clear, and exact description of the same, reference beinghad to the accompanying drawings, forming part of this specification, in which- Figure l is a side elevation of my improved dred gin g-m achine, shown attached to the stern of a boat. Fig. 2 is an edge view. Fig.3 is a plan view. Fig. 4 is a detail sectional view of one of the drums.

My invention relates to improvements in machinesfor dredging oysters or other shellfish; and it consists of an inclined endless rake provided with tines, operated by suitable mechanism, and secured to a vessel at one end and having its opposite end resting on the water-bed to be dredged.

My invention further consists in certain details of construction,hereinafter more fully set forth.

In the accompanying drawings,a represents a vessel, to the stern of which is journaled in suitable bearings a cylinder, b, provided with longitudinal teeth 0 along its periphery.

d d represent a series of transverse slats connected together at their opposite ends by the links 6 0, thus forming an endless chain,g.

It represents a hollow water-tight cylinder, provided with longitudinal teeth 5 along its periphery.

The endless chain g passes around the cylinders b h, and power applied to the cylinder bwill impart arevolving movement to the endless chain, the teeth in both cylinders engaging in the openings between the slats of the endless chain in its revolution. Each slat d of the endless chain is provided with a series ofparallel curved tines or teeth, 0, adapted in the revolving movement of the endless rake, having its lower end resting on the bottom, to raise the oysters or other shell-fish from the bottom of the stream and carry them into the vessel.

The lower cylinder, h, is made water-tight, in order to render the dredge more buoyant, and to relieve it of a part of its weight and prevent it from sinking in the mud. The upper cylinder, I), may also, if it be desired, be made hollow for the introduction of steam in winter, to remove ice from the periphery of the cylinder and its teeth, and also from the endless chain. Power is applied to the shaft of the upper cylinder in any suitable manner. The cylinders b h are secured together and held apart by means of the braces i i, secured to the shafts of both cylinders and the diagonal braces jj.

k krepresent arms secured to the axle of the lower cylinder, h, at its opposite ends.

Z represents a rake-head, preferably made of wood, so that, if broken, it may readily be replaced, and journaled in the outer ends of the arms k.

m m represent rake-teeth, each formed of an elastic piece of metal wound around the rakehead, and adapted to yield when meeting a heavy obstructionas a rock,&c.--and at the same time adapted in the forward movement of the vessel to rake oysters or other shell-fish and deliver them to the curved teeth of the endless rake,the latter also conveying oysters to the vessel independently of the stationary rake. The teeth of the stationary and endless rakesbreak joints with each other. The teeth of the endless rake are preferably spring-teeth.

n represents a cable, by means of which the dredge is hauled on board the vessel when desired.

I am aware that excavators and dredgingmachines have heretofore been provided with an endless belt having curved buckets secured thereto, which, in the revolution of the belt, are adapted to excavate and raise the excavated soil, and I therefore lay no claim to such construction, which differs from my invention in that I employ a series of curved tines or teeth, instead of buckets, on my endless belt, which do not raise the mud at the bottom of the stream dredged, as in the inventions disclaimed, but separate the mud from the oysters and raise only the oysters, the mud passing between the tines or teeth.

I claim as my invention- 1. The combination, with a vessel, of an inclined endless oyster-rake havinghookedtines, substantially as described, and for the purpose set forth.

2. The combination, with a vessel and an inclined endless rake having hooked tines, of

a stationary rake provided with tines and secylinders b h,0f the arms 1-: k, rake-head I, and 10 cured to the lower end of the endless rake, subspring rake-teeth m, substantially as described, stantially as described. and for the purpose set forth.

3. The combination, with the vessel a, end- The above specification of my invention less rake g, armed with teeth, and cylinder I), signed by me this 12th day of July, A. D. 1881. of the hollow water-tight cylinder h, substan- W. B. COLLIER. tially as described.

4. The combination, with the vessel a, endless rake g, having curved tines 0, and hollow Witnesses:

SoLoN O. KEMoN, CHARLES W. PETTIT. 

